Biomolecules (food) Flashcards
Two main reasons why living organisms require food?
1)respiration
2)growth and repair
6 most common elements found in food
1)Carbon
2)Hydrogen
3)Oxygen
4)Phosphorus
5)Sulfur
6)Nitrogen
4 groups of biomolecules present in food
1)Carbohydrates
2)lipids
3)protein
4)vitamins
5 elements and minerals that are present as dissolved salts in organisms
1)Sodium
2)Magnesium
3)chlorine
4)potassium
5)calcium
3 elements/minerals that are only found in tiny amounts
1)Iron
2)Copper
3)Zinc
What are the main components of carbohydrates?
Carbon, hydrogen and oxygen
What is the ratio of hydrogen to oxygen?
2:1
What is the formula of carbohydrates?
Cx(H2O)y
Name the three carbohydrates
Monosaccharides, Disaccharides and Polysaccharides
How many sugar units are in monosaccharides?
One sugar unit
What are examples of monosaccharides?
Glucose and fructose
How many sugar units are in disaccharides
Two sugar units
Examples of disaccharides
Maltose, Sucrose and lactose
Examples of polysaccharides
Starch, glycogen and cellulose
What carbohydrate is used by organisms for respiration?
Glucose
What type of polysaccharide is starch
A storage polysaccharide in plants
Where is starch mostly stored in
Ground tissue cells
What is starch made up of
Many glucose molecules
What type of polysaccharide is starch?
A storage polysaccharide found in animals
Where is glycogen stored in?
Liver and muscle
What is glycogen made up of?
Many glucose molecules
What type of polysaccharide is cellulose?
A structural polysaccharide in plant cell walls
What is the function of glucose?
Respiration to release energy
What is the function of cellulose in a human
Is roughage in the human diet (prevents constipation)
Name foods rich in carbs?
1)Fizzy drinks have glucose
2)milk has lactose
3)table sugar has sucrose
4)potatoes and bread have starch
5)wheat has cellulose
What is the enzyme that digests starch?
Amylase
Where is salivary amylase found in?
The mouth
Where does salivary amylase work in?
Mouth
Where is pancreatic amylase produced in?
Pancreas
Where does the pancreatic amylase work in?
Duodenum
What is the optimum pH of amylase?
7-9
What reagent is used to test for starch?
Iodine
What is the result for the test for starch if present and if not present
1)If starch present iodine turns blue black
2)If iodine remains red-brown if starch is not present
What is a reducing sugar?
Sugar when heated with blue Benedict’s solutions turns the solutions brick red
Examples of reducing sugars
Glucose and fructose
What reagent is used to test for a reducing sugar?
Benedicts solution
What is a special condition when testing for a reducing sugar?
Heat is required
What is the result when testing for a reducing sugar?
Blue Benedict’s solution turns brick red
Distinguish the difference between a fat and a oil
Fat is solid at room temperature
Oil is a liquid at room temperature
What are lipids composed of?
Carbon hydrogen and oxygen
What is the ratio of hydrogen to oxygen in lipids?
No fixed ratio
What is the basic unit that makes up lipids?
Triglycerides
What is the composition of triglycerides?
Glycerol and 3 fatty acids
Where are triglycerides found in animals (2 features)?
1)Adipose tissue under the skin
2)surrounding internal organs
Give a function of triglycerides in cells?
Metabolic function stored as an energy source
Give two other functions other then energy of triglycerides in animals?
1)insulation
2)protect vital internal organs
What is the composition of a phospholipid?
Glycerol, two fatty acids and a phosphate
Where are phospholipids found?
Membranes of cells
What is the function of phospholipids?
Structural role in membranes
How do phospholipids differ from fats in terms of chemical components?
1)Phospholipids contain phosphorus unlike fats
2)phospholipids have two fatty acids, fats have three
What do carbohydrates and fats have in common in terms of chemical compositions?
Both contain hydrogen, carbon and oxygen
How do carbohydrates and fats differ from eacjotehr In terms of chemical components
1)Carbohydrates ratio of hydrogen and oxygen is 2:1
2)Fats have no ratio
Name foods rich in lipids?
Butter? milk and cheese
What enzyme digests lipids?
Lipase
Where is pancreatic lipase produced in?
Pancreas
Where is pancreatic lipase work in?
Duodenum
What is the optimum pH of lipase?
7-9
What reagent is used to test for fat?
Brown paper
What is the result when testing for fat?
A permanent translucent stain
What is the conclusion when testing for fat?
Butter and oil have fat
Water does not have fat
What is protein composed of?
Carbon, hydrogen, oxygen and nitrogen
What else is protein composed of which is found in tiny amount?
Sulfur
What are proteins made of?
Long chains of different amino acids
What is an amino acid
Smaller unit from which all proteins are made up
How do amino acids differ from carbohydrates and lipids?
It contains nitrogen
How do amino acids differ from carbohydrates and lipids?
It contains nitrogen
Apart from protein, name another biomolecule that contain the element nitrogen
Nucleus acids
How many common amino acids are found in proteins
Twenty
What is a peptide?
Small chain of amino acids (less then 20)
What is a polypeptide?
Longer chain of amino acids (more then 20)
Name foods rich in protein
Meat, fish and eggs
Where in a cell are all proteins produced?
Ribosome
Name 3 fibrous (structural) roles of proteins in animals
1)Keratin which is found in hair nails and skin
2)collagen found in skin
3)myosin found in muscle
Name 3 metabolic roles of proteins in animals?
1)Enzymes
2)antibodies
3)many hormones
Example of a metalloprotein in animals
Haemoglobin contains iron
What enzyme digests protein?
Pepsin
Where is pepsin produced?
Stomach
Where does pepsin work in?
Stomach
What is the optimum pH of pepsin
1-2
What name is given to the inactive form of pepsin?
Pepsinogen
What reagent is used to test for protein
Biuret reagent
What is the result when testing for protein?
A purple colour is obtained
What is a control in a scientific experiment?
Experiment that acts as a comparison which provided proof that the results are valid
What are vitamins?
Needed in tiny amounts that organisms cannot make themselves
How are vitamins classified?
Water soluble or fat soluble
Name a water soluble vitamin?
Vitamin C
Name a fat soluble vitamin?
Vitamin D
What is the function of vitamin C?
Make connective tissue
What are some dietary sources of vitamin C?
Citrus fruits such as kiwi and lemons
Name a deficiency disease associated with a lack of vitamin C
Scurvy (gums bleed and bruise easily)
What is the function of Vitamin D?
Absorption of calcium
Dietary sources of vitamin D?
Milk and eggs
Name a deficiency disease associated with lack of vitamin D
Rickets in children (deformed bones)
What are minerals?
Inorganic elements essential for organisms
Name 3 elements present in dissolved salts
1)Sodium
2)magnesium
3)chlorine
Name three minerals required in trace amounts?
Iron copper and zinc
What is the function of iron
Make haemoglobin in red blood cells that transport oxygen
Name a deficiency disease from a lack of iron
Anemia (pale and tired)
What is the function of calcium
Needed for strong bones and teeth
What are the sources of calcium?
Milk yogurt and cheese
Name a deficiency disease from a lack of calcium?
Osteoporosis (weak brittle bones)
Name three minerals required by plants and give its function
1)Nitrates-production of plant proteins
2)magnesium-production of chlorophyll
3)calcium-essential in cell walls
By what process do minerals enter the plant through soil
Active transport
What is the percentage of water in most living things
75-95%
Outline the role of water in living things
1)water is the meduim in which metabolism occurs
2)excellent solvent
3)required for photosynthesis
4)excellent absorber of heat (keeps body temperature stable)?
5)keeping plants turgid
How many sugar units does polysaccharides have?
Many sugar units
